The present invention relates to a heat seal capping head assembly for use in forming a heat sealed closure having a central portion and a skirt for bottles, jars, cans and similar containers.
In one aspect of the invention, there is provided an apparatus for heat sealing supported plastic films such as polyethelene-lined aluminum foil bottle caps to the neck or pouring lip of a bottle made of polyethelene, and containing liquids such as milk, carbonated beverage, or the like, in connection with which the invention will be described.
The use of all-plastic bottles as fluid containers has been widely accepted, and has brought with it service conditions which require an extremely tight seal or closure at the lip or pouring edge of the bottle. The testing and service features associated with all-plastic containers are rigorous, and involve taking an all-plastic bottle and squeezing it as hard as possible to see if the closure or cap can be made to leak. It has been suggested to seal the cap to the bottle itself in order to meet the stringent fluid-tight requirements of the industry. The use of a heat sealing film means, of course, that the bottle has to be compatible with the heat seal cap so that sealing may be effected. Thus, for example, a polyethelene film inside an aluminum bottle cap will heat seal effectively to the polyethelene bottle, thereby meeting the requirements for the service use of the all-plastic container.
In order to obtain maximum use of equipment presently available to bottlers, it is particularly desirable that the heat sealing means be incorporated into a device similar to a conventional filling machine wherein bottles are moved by an indexing device through a series of stations. Utilizing the subject invention, as each bottle progresses through each station, one phase of the heat sealing procedure takes place, and at the end of the heat sealing operation the all-plastic bottle is returned to a conveyor means and carried away to a point where it may be readily packaged and loaded for transport to the consumer outlet.